1. Field of the Invention
This invention relates to a color signal adjustment device used in, for example, a camera device.
2. Description of the Related Art
There is known a camera device in which red (R), green (G) and blue (B) color signals, obtained on imaging an object, are processed with chroma signal processing for generating (R-Y) and (B-Y) color difference signals. In this camera device, the (R-Y) and (B-Y) are found by the following equations: EQU R-Y=X.vertline.(R-G)+Z(B-G).vertline.
where X: gain of the (R-Y) signal and PA1 Z: phase of the (R-Y) signal EQU B-Y=X.vertline.(B-G)+Z(B-G).vertline. PA1 where X: gain of the (B-Y) signal PA1 Z: phase of the (B-Y) signal. PA1 where X: gain of the (R-Y) signal PA1 Z: phase of the (R-Y) signal; and EQU B-Y=X{(B-G)+Z(R-G)} PA1 where X: gain of the (B-Y) signal; and PA1 Z: phase of the (B-Y) signal.
Therefore, in adjusting the color signal using these color signals, the signs of the (R-G) signal and the (B-G) signal as parameters are discriminated for deciding whether these signals define the (R-Y) signal or the (B-G) signal. Subsequently, the coefficients of X and Z are determined. That is, if the sign of the (R-G) signal is plus or minus, the gain of the (R-Y) signal becomes positive or negative, respectively. On the other hand, if the sign of the (B-G) signal is plus or minus, the phase of the (R-Y) signal becomes positive or negative, respectively.
Similarly, if the sign of the (R-G) signal is plus or minus, the phase of the (B-Y) signal becomes positive or negative, respectively. On the other hand, if the sign of the (B-G) signal is plus or minus, the gain of the (B-Y) signal becomes positive or negative, respectively.
After the signs of the gain and the phase are set in this manner, X and Z are set.
However, since the (R-Y) and (B-Y) signals have the (R-G) and (B-G) signals as parameters, respectively, as described above, the phase of the (B-Y) signal is increased if the gain of the (R-Y) signal is increased, such that the phase or the gain, which are not desired to be adjusted, are undesirably changed.
On the other hand, there are eight parameters of the (R-Y) and (B-Y) signals in all, as described above, such that, if each parameter is of one bit, eight bits are perpetually required. The result is that, if color signal adjustment employing the above-mentioned eight color difference signals for each pixel, the information volume becomes excessive, thus delaying the transfer rate of each parameter.